op detroit



Jan. 1, 1929.

E. E. VVAJQE METHOD AND APPARATUS FOR THE MANUFACTURE OF VARNISH FiledJune 23, 1924 r w m v V Z W Q s U M Q rm y a Patented Jan. 1, 1929.

UNITED STATES PATENT OFFICE.

ELMER E. WARE, OF DETROIT, MICHIGAN, ASSIGNOR T0 ACME WHITE LEAD ANDCOLOR WORKS, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

METHOD AN D APPARATUS FOR THE MANUFACTURE OF VARNISH.

Application filed June 23, 1924. Serial No. 721 ;902.

The invention relates to the manufacture of varnish and has for itsprimary object the obtaining of a continuous process for manufacturingthe same as distinguished from the usual intermittent or batch process.

Amongst the advantages derived from my new process are first, theuniformity of theproduct due to the accurate control of compositions,temperatures, and treatments; second, the improvement in the quality ofthe varnish because of the elimination of deleterious oxidation of oilsand resins, .and also because the raw'materials are subjected toindividual treatments uninfiuenced by the other ingredients; and third,the reduction of cost through the elimination of unnecessary handling ofmaterials and apparatus, through increase of 'output per unit equipment,through elimination of repair charges incident to the operation ofkettles and trucks in contact with the intense heat of the cooking firesof the batch process, and the saving of fuel by avoiding theintermittent heating and cooling of the apparatus.

In order to more fully understand the new process it may be stated thatvarnish is essentially a solution of a resin in an oxidi'zable oil orvolatile solvent or both, the subsequent volatilization of the solventand oxidation of the oil resulting in a thin film of protective materialon the surface. to which the varnish has been applied. The resin may bea natural product or. a synthetic product depending upon the type ofvarnish to be produced and is sometimes given a preliminary heattreatment to increase its solubility. The oil is generally, although notnecessarily, bodied either before or after the solution of the resin,this bodying being accomplished by heating to a predeterminedtemperature. The bodying is generally considered as a polymerizationaccompanied by a partial oxidationalthough the oxidation is believed tobe disadvantageous. v

In the present state of the art the varnish is manufactured by anintermittent process,

the batches varyin insize from fifty (50) to twelve hundred (1200) ormore gallons in .size, according to the nature of. the productv and thetype of the kettle used. The'smaller size batches are ordinarily made inportable kettles, While the -larger ones require a stationary or setkettle installation in which the batch may be reduced as well as cookedbefore leavingthe kettle. Assuming that the raw materials are of astandard quality the uniformity and quality of the resultant varish madein either installation depends upon the accuracy of proportioning theraw materials entering into the batch and the control of the heattreatment of the oils and gums. These two important factorsarcinfluenced by the personal equation of the operator in charge of eachkettle.

In the new process the raw materials pass in a continuous stream througha series of kettles or other containers in which the various stages ofheattreatment are carried out. Each step requiring an individualtreatment has assigned to it a special kettle finished product isdischarged in such quanti-' ty as is required by the particular formulaunder manufacture at the time. In this way each raw material may betreated free from the deleterious influence of any other material orfrom undue oxidation, the latter being accomplished by the sealing ofthe heating chamber. Furthermore, the heating chambers may, if desired,be operated under vacuum to accelerate reaction or may be subjected toair blast to promote oxidation in certain cases. The compositions of thevarnishes made by this process are controlled by synchronizing thedischarge of the several feeders handling the raw or semi-finishedingredients. It is prefer-able also to control the heat treatmentthrough variation in quantity of flow and since temperature is animportant factor in the heat treatment the process lends itself readilyto automatic control by providing a thermostat to'regulate the rate offlow.

In the drawings:-

Figure 1 illustrates diagrammatically the apparatus used for carrying onthe process;

Figure 2 is a diagram illustrating the automatic control of the oilfeeding and resin feeding devices' Figures 3 and 1 show the contact armsof thethermostatically controlledjswitch in the two positions.

. As an example of the operation of the new process, the followingdescription is given of the steps for producing a black baking japanmade from the following ingredients Asphaltum gum 200 lbs. Perilla oilgals. Linseed oil 20 gals. Turpentine 100 gals. Metallic drier 2lbs.

The two oils are mixed in proper proportion s'in each of the supplycontainers A and A controlled by the valves B and B and preferablyprovided with steam heating coils B for maintaining the oil at asubstantially constant temperature. A centrifugal pump C is arranged towithdraw the oil from said tanks and deliver an excess quantity to astandpipe D equipped with a pressure or head controlling device D havingan overflow pipe D for returning the excess oil to the inlet side of thepump 0. As shown in Figure 1 the height of the liquid in the standpipe Dis controlled by raising or lowering the container D by means of themovable support E slidable upon a bearing E and actuated by the screw Erotated in the threaded member E b the reversible motor N. A flexiblepipe connects the container D with the standpipe D, preferably at apoint not immediately adjacent the. inlet to said standpipe nor to theoutlet F From the stand pipe the oil flows through calibrated orifice Hand meter H. For practical purposes, the

orifice may be made adj ustable by making it an integral part of anadjustable stopcock,

which is in the case in question adjusted to' the predetermined capacityby means of the meter.

G is a tank containin oil orsome other suitable heating material ormaintaining a uniform temperature in the coil pipe G connected tothemeter H. A burner Gr or other suitable means is provided for heating themedium to the proper temperature and a mechanical agitator G isplaced'within the coil G to continuously circulate the beating mediumaround the coils. erably provided withv the blades G? so arranged as tocirculate the heating medium downward through the coil G and is drivenby any suitable mechanical means (not shown The purpose of thisapparatus is to pre-heat the oil to a temperature sufliciently iigh toenable the second kettle to operate at a uniform temperature throughout.The temperature of the first kettle is usually, although notnecessarily, maintained below the point where any appreciable reactiontakes place within the oil, for example, a temperature of 525-550 F.From the coil G the mixed oils pass .into a reaction tank I providedwith a series of cylindricalbaffles I so arranged as to cause an up anddown circulation. The oil is preferably introduced .centrally of theapparatus, passing through the apertures I asgshown by the arrows.finally This agitator is prefreaching the outer' cylindrical space fromwhich an overflow pipe I leads to the succeeding unit J. A suitableburner I is ar-- to the bottom of the tan The outlet of the tank J isnear the top of the baffle tube J thereby protecting the finishedmixture from undue agitation. Arranged above the tank J is a feedingapparatus K for discharging the proper amount of resin or asphaltum gumto be incorporated into the varnish. The feeder is arranged to becontinuouslyoperated so as to discharge the gum at a rate proportionalto the flow of oil through the apparatus. For this purpose, asuitable-regulating device is provided and as diagrammatically shown,comprises a rotatable member K having recesses K therein, this memherbeing housed in a cylindrical housing K connected to a hopper K Adischarge conduit K leads to the tank J and the member is rotated by amotor K through suitable gearing K. The gum is melted upon reaching thesolution by the mechanical agitator, heat being also supplied to thetank through a suitable burner J The overflow from the unit J passesinto an accumulator tank L, which serves merely to collect the mixedproduct and to periodically discharge the same into the thinning vats(not shown) by the operation of the manually controlled valve L. Theconduit L through which the material enters the accumulating tankpreferably extends to the bottom of the tank L in order to maintain aliquid seal at all times to avoid flashing. A burner L is also providedunder the tank L to maintain the mixture sufficiently fluid fortransferring.

With the apparatus as thus far described, the flow of oil is regulatedby the height of the liquid in the head controlling device D actingthrough the calibrated orifice H,

and by maintaining a uniform tempera ture of the oil passing through theorifice a very accurate control may be obtained.

In order to accurately control the tem-- Hill able thermostaticregulator M near the outlet of the tank I which is adapted to operate'through suitable electrical connections to control the operation of themotor N and the speed of the motor K n arrangement is provided foraccomplishing this purpose and is -diagrammatiof the thermostat Mcontrols a reversing switch M electrically connected to the motor N soas to energize the same either in the forward or the reverse directionaccording to the position of the switch M. also 'is electricallyconnected to a reversible motor adapted to control the field resistanceQ of the motor K so as toincrease or decrease the speed of said motor.Thus, as shown, the motor 0 is electrically connected to a rotatablescrew R threadedly engaging the movable contact P. This contact istherefore, moved in one direction or the other, according to'therotation of the motor 0 and consequently increases or decreases thefield Q, thereby correspondingly changing the speed of the motor Kdriving the rotatable regulator K. Srepresentsa manually operable switchfor controlling the operation of the motors N and O, in case it isdesired to eliminate the thermostatic control. Electri v cal apparatusof the character diagrammatically illustrated in-Figure 2 iscommercially obtainable and what I wish to-illustrate is merely anapparatus for simultaneously regulating the efi'ectivehead upon theorifice and the feed for the resin or asphaltum gum.

With the arrangement as described, both of these variables arecontrolled by the temperature of the liquid in the tank I and both aremaintained operating atproportionate rates.

' 15 contact with the A more specific description of the electriccircuits represented in Figure 2 is as follows The switch M comprisesfour contact points 10, 11, 12 and 13 and the contact arms 14 and 15,thelatter-being pivoted respectively at 16 and 17 and being connected tothe thermostatM by arms 18 and 19. The arrangement is such that uponmovement'of the thermostat in one direction arms 14 and points 10 and 13respectively, as shown in Figure 3, while in the other direction thearms contact with the points 11 and-12 respectively as shown in Figure4. The contacts 10 and 12 are connected together and contacts 11 and 13also are connected together. motor 0, has its terminals 21 and 22,respectively connected to points 10 and 11, while the armature 23 of themotor has its terminals 24 and 25 connected respectively to points 10and 11. The fields 26 and 27 of the respective motors O and 'N areconnected'in' mul tiple between the positive terminal and the contactarm 15, while the negative terminal is connected directly with thecontact arm- 14. The motor K is arranged in a circuit 28 includingthefield resistance Q and the manually controlled switch 29. The switch Sis similar to the switch M except that it is manually controlled, andthe various elements of the switch S are connected to the correspondingelements of the switchM' so This switch When the reversing switch M isin the posi- 7 tion shown in Figure 3, current from the positiveterminal will pass through the fields 26 and 27 which are in parallel,the contact arm 15, contact point 13, then dividing and passing througharmatures 20 and 23 respectively and finally returning to the contact 10where the circuit is completed to the negative terminal through theswitch arm 14. Thus the motors O and N will be energized and revolve incertain predetermined directions, the former adjusting the fieldresistance Q and the latter adjusting the height of the. bracket E. Whenthe thermostat is moved in the opposite direction to: the position shownin Figure 4, it will be obvious that the switch arm 15 now contacts withthe point 12, while the switch arm 14 contacts with point 11. In thisposition of adjustment, the flow of current through the fields 26 and-27takes place in the same mannerlas in thc preceding adjust-- ment, butwhen the switch arm' 15 is reached, it will'be obvious that the flowthrough the armatures20 and 23 will be in the reverse I direction fromthe preceding arrangement. Therefore, the motors O and N by having thepolarities on the armatures changed will rotate in the, reversedirection. switch M is in the position shown in Figure.

2 with'the contact arms 14 and 15 in neutral I position, no current willflow through either of the motors O and N and the latter will remainstationary. In this stationary position the motor K still operates at aprede- When the termined speed depending upon the adjust-,

ment of the field resistanceQ and the arm'E remains at a predeterminedheight so as tomaintain a predetermined head upon the calibrated orificeI-I. J

a In the making of various types of varnish, The armature 20 of the thenecessary amount of surface, The kettlemay be and preferably is madefrom metal not attacked by oils or gums if suflicient surface isotherwise provided. In the particular process described it'has beenfound that any iron surface will supply the necessary sicca-, tive forthe process. I i Thematerial collected in theaccumulating unit L mustordinarily be mixed with a thinnerlfor producing a' commercial varnish,but

loo

this apparatus forms no part of my invention and the usual method may beemployed of mixing the product obtained in the above de-' scribedprocess with a Volatile thinner in large stationary tanks.

While I have specifically described the process as applicable to themanufacture of a baking japan, it Will be understood that this processis also applicable to making a largenumber of other types of varnish,and in modifying this apparatus for these other speclfic types, it isonly necessary to provide units for carrying on the heat treatments andthe mixing of the raw materials entering thereinto. Each of the heattreatment kettles is heated to a predetermined temperature.

covers andoperate either under vacuum to accelerate the reactions orunder an air blast to promote oxidation if desired.

It will also be obvious that instead of employing the motors N and O forregulating the hydrostatic head and the feeding'of the resin, suitablemanually operable means may be employed if desired. This apparatus,howeverrwould require more attention upon the part of the operator thanthe thermostatically controlled apparatus which is the preferred form.

While I have illustrated the pre-heated tank G as being composed of acoil G surrounded by an oil bath, in the making of certain typesof'varnish, it is not necessary to employ a coil, but the oil maybecaused to flow directly into the tank G/ and the tem- I perature will bemaintained sufiiciently constant because of the agitator G In theappended claims the term resin is used to define either arnatural or asynthetic product, and includes Within its scope asphaltum gum and anyother products that are dissolved in oils or volatile solvents for thepurpose of obtaining varnish. Likewise the terms liquid varnish-makingingredient and varnish-making oil are intended to cover either anoXidizable oil or a volatile solvent or both. v

What I claim as my invention is 1. The process of making varnishconsisting in passing a liquid varnish-making ingredient in a continuousstream through a series of containers, subjecting said liquid to predetermined pressures and temperatures during the passage, introducing,a'resin ingredient into said stream .at a rate substantiallyproportionate to the rate of flow of said liquid ingredientsynchronously varying theflovy of said liquid ingredient and said resiningreclient to maintain uniformity in the proportion of ingredients andthe heat treatment thereof.

2. The process of makin varnish consisting in passing a varnish-ma ingoil in a continuous stream through a series of containers, subjectingthe oil to heat treatment during the passage continuously introducing aresin thereinto at a rate substantially proportionate to the flow ofsaid oil, automatically varying the flow of oil to maintain a uniformtemperature during heat treatment, and automatically varying the amountof resin introduced to maintain a uniform proportion of ingredients.

3. The process of making a varnish consisting in passing avarnish-making oil through an apparatus in a continuous stream,subjecting the stream to heat treatment, continuously introducin resininto said stream at a predetermine point in its passage, varying therate .ofoil flow to control the reactions in said apparatus andmaintaining a substantially constant proportion of ingredients.

4. The process of making a varnish consisting in continuously passing avarnish making oil through a series of containers, introducing resininto one of said containers at a proportional'rate to the oil,subjecting the ingredients to predetermined conditions of temperaturepressure and agitation in the 'respectivecontainers to efiect thereactions,

and controlling the reactions in said containers by varying the rates offlow of the oil and the resin while maintaining the same insubstantially proportionate relation to each other.

51 An apparatus for producing varnish comprising a series of containersconnected by conduits, each. of said containers being provided withmeans for subjecting the contents thereofto a predetermined condition oftemperature pressure and agitation, means for effecting a flow of avarnish-making 011 through said apparatus, means for automaticallyvaryingthe flow of oil to maintain a substantially constant temperatureand means for introducing resin therein at a rate substantiallyproportionate to the rate offlow of said oil.

I 6. The process of makingvarnish which consists in subjecting avarnish-making oil to a variable hydrostatic head passing the oilthrough a calibrated orifice into a mixing apparatus While maintaining asubstantially constant heat-supply, subjecting said oil to' a heattreatment in said apparatus, introducing resin into said oil and varyingthe hydrostatic headefiective upon said calibrating orifice to controltherateof flow through said apparatus to the amount required to maintaina constant temperature in the mixing apparatus.

7. The process of making varnish which consists in continuously feedingthe ingredients of the varnish into a mixing apparatus, subjecting thematerials to heat treatments during the passage thereof through theapparatus, and controlling the temperature of the reaction by increasingor decreasing the feed of the respective ingredients into the apparatus.

8. The process of making varnish which consists in passing a liquidvarnish-making ingredient in a continuous stream through a series ofcontainers, to predetermined pressures and temperatures during thepassage, introducing a second ingredient into said stream at a rateproportionate to the rate of flow of said liquid ingredient andcontrolling the reaction by insubjecting said liquid creasing ordecreasing the rate of flow of the ingredients through the apparatus.

9. An apparatus for manufacturing varnish comprising a varnish-makingoil reservoir, means for maintaining oil under predetermined hydrostaticpressure, a pre-heating unit connected to said oil reservoir, a heattreating unit connected to said pre-heating unit, baflles in said heattreating unit forming passages therein, a mixing apparatus connected tosaid heat treating unit, means for feeding solid material into saidmixing apparatus, and means for regulating the hydrostatic to controlthe ow of oil thereto In testimony whereof I aflix my signature.

ELMER E. WARE.

ressure upon said apparatus

